That's because depreciation is a paper loss. If you're an average person you're not selling your car for a new one for at least 7-8 years after you buy it. By that time it's worth very little of its original cost anyways. The only actual cost incurred by the driver is repairs and maintenance, which is nowhere near the cost of depreciation on the car. In effect, the depreciation schedule changes, but on the time scales of your average person the net result after 7-8 years of ownership is the same total depreciation. For corporate owners who have to report depreciation as a loss this schedule is not great, but for individuals it's not a real loss.
Mileage driven depreciation is a real loss until the car is fairly old: More miles directly reduces the price you can get selling the used car. Uber won't accept drivers driving old beaters where that curve has flatted out.
According to KBB a 2010 Toyota Prius (just selected as an example) only has a price estimate differential of $3000 between 100k miles and 400k miles. Even if you bump that up to 5k for a newer car, it's still insubstantial compared to the overall depreciation on the car from its new value of ~$25k to a 8-year used value of 3-6k. That 20k extra depreciation is not recognized by individuals but is by corporate owners.
